电可切换光致发光活性：[Re(bpy)(CO)₃(C≡C≡C₆H₄≡C≡C)Fe(C₅Me₅)(dppe)][PF₆](n)（n = 0, 1）的合成、光谱学、电化学、光物理学以及X射线晶体结构和电子结构

Electroswitchable photoluminescence activity: synthesis, spectroscopy, electrochemistry, photophysics, and X-ray crystal and electronic structures of [Re(bpy)(CO)3(C[triple bond]C[bond]C6H4[bond]C[triple bond]C)Fe(C5Me5)(dppe)][PF6](n) (n = 0, 1).

作者信息

Wong Keith Man-Chung, Lam Sally Chan-Fung, Ko Chi-Chiu, Zhu Nianyong, Yam Vivian Wing-Wah, Roué Séverine, Lapinte Claude, Fathallah Sofiane, Costuas Karine, Kahlal Samia, Halet Jean-François

机构信息

Centre for Carbon-Rich Molecular and Nano-Scale Metal-Based Materials Research and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong.

出版信息

Inorg Chem. 2003 Nov 3;42(22):7086-97. doi: 10.1021/ic030226d.

DOI:10.1021/ic030226d

PMID:14577776

Abstract

A novel heterobimetallic alkynyl-bridged complex, [Re(bpy)(CO)(3)(C[triple bond]C[bond]C(6)H(4)[bond]C[triple bond]C)Fe(C(5)Me(5))(dppe)], 1, and its oxidized species, [Re(bpy)(CO)(3)(C[triple bond]C[bond]C(6)H(4)[bond]C[triple bond]C)Fe(C(5)Me(5))(dppe)][PF(6)], 2, have been synthesized and their X-ray crystal structures determined. A related vinylidene complex, [Re(bpy)(CO)(3)(C[triple bond]C[bond]C(6)H(4)bondC[double bond]C)Fe(C(5)Me(5))(dppe)][PF(6)], 3, has also been synthesized and characterized. The cyclic voltammogram of 1 shows a quasireversible reduction couple at -1.49 V (vs SCE), a fully reversible oxidation at -0.19 V, and a quasireversible oxidation at +0.88 V. In accord with the electrochemical results, density-functional theory calculations on the hydrogen-substituted model complex Re(bpy)(CO)(3)(C[triple bond]C[bond]C(6)H(4)[bond]C[triple bond]C)Fe(C(5)H(5))(dHpe) (Cp = C(5)H(5), dHpe = H(2)Pbond(2)[bond]PH(2)) (1-H) show that the LUMO is mainly bipyridine ligand pi* in character while the HOMO is largely iron(II) d orbital in character. The electronic absorption spectrum of 1 shows low-energy absorption at 390 nm with a 420 nm shoulder in CH(2)Cl(2), while that of 2 exhibits less intense low-energy bands at 432 and 474 nm and additional low-energy bands in the NIR at ca. 830, 1389, and 1773 nm. Unlike the related luminescent rhenium(I)-alkynyl complex [Re(bpy)(CO)(3)(C[triple bond]C[bond]C(6)H(4)[bond]C[triple bond]C[bond]H)], 4, complex 1 is found to be nonemissive, and such a phenomenon is attributed to an intramolecular quenching of the emissive d pi(Re) --> pi*(bpy) (3)MLCT state by the low-lying MLCT and LF excited states of the iron moiety. Interestingly, switching on of the luminescence property derived from the d pi(Re) --> pi*(bpy) (3)MLCT state can be demonstrated in the oxidized species 2 and the related vinylidene analogue 3 due to the absence of the quenching pathway.

摘要

一种新型的异双金属炔基桥联配合物[Re(bpy)(CO)₃(C≡C≡C₆H₄≡C≡C)Fe(C₅Me₅)(dppe)]（1）及其氧化产物[Re(bpy)(CO)₃(C≡C≡C₆H₄≡C≡C)Fe(C₅Me₅)(dppe)][PF₆]（2）已被合成，并测定了它们的X射线晶体结构。还合成并表征了一种相关的亚乙烯基配合物[Re(bpy)(CO)₃(C≡C≡C₆H₄≡(H)C═C)Fe(C₅Me₅)(dppe)][PF₆]（3）。1的循环伏安图显示在-1.49 V（相对于SCE）处有一个准可逆还原偶，在-0.19 V处有一个完全可逆氧化，在+0.88 V处有一个准可逆氧化。与电化学结果一致，对氢取代的模型配合物Re(bpy)(CO)₃(C≡C≡C₆H₄≡C≡C)Fe(C₅H₅)(dHpe)（Cp = C₅H₅，dHpe = H₂P(CH₂)₂PH₂）（1-H）进行的密度泛函理论计算表明，最低未占分子轨道（LUMO）主要具有联吡啶配体π的特征，而最高已占分子轨道（HOMO）主要具有铁（II）d轨道的特征。1在CH₂Cl₂中的电子吸收光谱在390 nm处有低能量吸收，在420 nm处有一个肩峰，而2的电子吸收光谱在432和474 nm处有强度较低的低能量带，在近红外区约830、1389和1773 nm处还有额外的低能量带。与相关的发光铼（I）-炔基配合物[Re(bpy)(CO)₃(C≡C≡C₆H₄≡C≡C≡H)]（4）不同，发现配合物1不发光，这种现象归因于铁部分的低能金属-配体电荷转移（MLCT）和配体场（LF）激发态对发射性的dπ(Re)→π(bpy)（³）MLCT态的分子内猝灭。有趣的是，由于不存在猝灭途径，在氧化产物2和相关的亚乙烯基类似物3中可以证明源自dπ(Re)→π*(bpy)（³）MLCT态的发光性质的开启。